/*
 * jQuery idleTimer plugin
 * version 0.8.092209
 * by Paul Irish. 
 *   http://github.com/paulirish/yui-misc/tree/
 * MIT license
 
 * adapted from YUI idle timer by nzakas:
 *   http://github.com/nzakas/yui-misc/
 
 
 * Copyright (c) 2009 Nicholas C. Zakas
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

(function($){

    function SEPARATOR() { return " "; }
    function IDLE_TIMER() { return ".idleTimer"; }

    $.idleTimer = function f(newTimeout) {

        //$.idleTimer.tId = -1     //timeout ID

        var idle    = false,       //indicates if the user is idle
            enabled = true,        //indicates if the idle timer is enabled
            timeout = 30000,       //the amount of time (ms) before the user is considered idle
            events  = "mousemove keydown DOMMouseScroll mousewheel mousedown", // activity is one of these events
          //f.olddate = undefined, // olddate used for getElapsedTime. stored on the function
            
        /* (intentionally not documented)
         * Toggles the idle state and fires an appropriate event.
         * @return {void}
         */
        toggleIdleState = function(){
        
            //toggle the state
            idle = !idle;
            
            // reset timeout counter
            f.olddate = +new Date;
            
            //fire appropriate event
            $(document).trigger( $.data(document,"idleTimer", idle ? "idle" : "active" ) + IDLE_TIMER());            
        },

        /**
         * Stops the idle timer. This removes appropriate event handlers
         * and cancels any pending timeouts.
         * @return {void}
         * @method stop
         * @static
         */         
        stop = function() {
        
            //set to disabled
            enabled = false;
            
            //clear any pending timeouts
            clearTimeout($.idleTimer.tId);
            
            //detach the event handlers
            $(document).unbind(IDLE_TIMER());
        },

        /* (intentionally not documented)
         * Handles a user event indicating that the user isn't idle.
         * @param {Event} event A DOM2-normalized event object.
         * @return {void}
         */
        handleUserEvent = function() {
        
            //clear any existing timeout
            clearTimeout($.idleTimer.tId);
            
            //if the idle timer is enabled
            if (enabled) {
                //if it's idle, that means the user is no longer idle
                if (idle) {
                    toggleIdleState();
                }

                //set a new timeout
                $.idleTimer.tId = setTimeout(toggleIdleState, timeout);
            }
        };

        /**
         * Starts the idle timer. This adds appropriate event handlers
         * and starts the first timeout.
         * @param {int} newTimeout (Optional) A new value for the timeout period in ms.
         * @return {void}
         * @method $.idleTimer
         * @static
         */
        f.olddate = f.olddate || +new Date;
        
        //assign a new timeout if necessary
        if (typeof newTimeout == "number"){
            timeout = newTimeout;
        } else if (newTimeout === "destroy") {
            stop();
            return this;  
        } else if (newTimeout === "getElapsedTime"){
            return (+new Date) - f.olddate;
        }
        
        //assign appropriate event handlers
        $(document).bind($.trim((events + SEPARATOR()).split(SEPARATOR()).join(IDLE_TIMER() + SEPARATOR())),handleUserEvent);
        
        //set a timeout to toggle state
        $.idleTimer.tId = setTimeout(toggleIdleState, timeout);
        
        // assume the user is active for the first x seconds.
        $.data(document,"idleTimer","active");
        
    }; // end of $.idleTimer()
})(jQuery);

